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13
Applications of Dietary
Reference Intakes for
Macronutrients
This chapter presents a general discussion of the appropriate uses of
the Dietary Reference Intakes (DRIs) in the assessment and planning of
diets for individuals and for groups. It also provides guidance for the use
of the DRIs developed for the nutrients presented in this report, including
specific examples and special considerations.
OVERVIEW
The Dietary Reference Intakes (DRIs) may be used for many purposes,
most of which fall into two broad categories: assessing current nutrient intakes
and planning for future nutrient intakes. Each category may be further
subdivided into uses for individual diets and for group diets (Figure 13-1).
For example, the Recommended Dietary Allowance (RDA), Estimated
Average Requirement (EAR), and Tolerable Upper Intake Level (UL) may
be used in assessing the diet of an individual as one aspect of a nutritional
status assessment. The RDA and Adequate Intake (AI) may be used as a
basis for planning a diet for the same individual. Likewise, the EAR and
UL are used to assess the nutrient intakes of a group, such as persons
participating in dietary surveys conducted as part of the National Nutrition
Monitoring System. The EAR and UL can also be used to plan nutritionally
adequate diets for groups, such as people receiving meals in nursing homes,
schools, prisons, and other group settings.
In the past, RDAs in the United States and Recommended Nutrient
Intakes (RNIs) in Canada were the primary reference standards available
936

937
A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
FIGURE 13-1 Conceptual frameworkâuses of Dietary Reference Intakes.
a Food plus supplements.
to health professionals for assessing and planning diets of individuals and
groups and for making judgments about inadequate and excessive intake.
However, neither the former RDAs nor the RNIs were ideally suited for
many of these purposes (IOM, 1994). The DRIs provide a more complete
set of reference values. The transition from using the former RDAs and
RNIs to using all of the DRIs appropriately will require time and effort by
health professionals and others.
Appropriate uses of each of the new DRIs are described briefly in this
chapter and in more detail in a report on the application of the DRIs in
assessment (IOM, 2000) and in a forthcoming report on their uses in
planning. Included in this chapter are specific applications to the nutrients
discussed in this report. Details on how the DRIs are set with reference to
specific life stage and gender groups, and the primary criterion that defines
adequacy for each of these nutrients are given in Chapters 5 through 10.
ASSESSING NUTRIENT INTAKES OF INDIVIDUALS
Dietary assessment methods have several inherent inaccuracies. One is
that individuals underreport their intakes (Mertz et al., 1991; Schoeller,

938 DIETARY REFERENCE INTAKES
1995; Schoeller et al., 1990), and it appears that obese individuals often do
so to a greater extent than do normal-weight individuals (Heitmann and
Lissner, 1995). There is no method to adjust intakes to account for under-
reporting by individuals and much work is needed to develop an acceptable
method. Another inherent inaccuracy is the quality of food composition
databases.
Furthermore, large day-to-day variations in intake, which are exhibited
by almost all individuals, mean that it often takes a prohibitively large
number of days of intake measurement to approximate usual intake
(Basiotis et al., 1987). As a result, caution is indicated when interpreting
nutrient assessments based on self-reported dietary data covering only a
few days of intake. Data on nutrient intakes should be interpreted in com-
bination with information on typical food usage patterns to determine if
the recorded intakes are representative of that individualâs usual intake.
Finally, because there is considerable variation in intakes both within
and between individuals, as well as variation associated with the require-
ment estimate, other factors must be evaluated in conjunction with the
diet. The Dietary Reference Intakes (DRIs) should be used in conjunction
with other data in assessing the adequacy of the diet of a specific indi-
vidual. The nutritional status of an individual can be definitively deter-
mined only by a combination of dietary, anthropometric, physiological
and biochemical data.
Using the Estimated Average Requirement and the
Recommended Dietary Allowance
The Estimated Average Requirement (EAR) estimates the median of a
distribution of requirements for a specific life stage and gender group, but
it is not possible to know where an individualâs requirement falls within
this distribution without further anthropometric, physiological, or bio-
chemical measures. Thus from dietary data alone, it is only possible to
estimate the likelihood of nutrient adequacy or inadequacy. Furthermore,
only rarely are precise and representative data on the usual intake of an
individual available, adding additional uncertainty to the evaluation of an
individualâs dietary adequacy.
An approach for using data from dietary records or recalls to estimate
the likelihood that an individualâs nutrient intake is adequate is presented
in Dietary Reference Intakes: Applications in Dietary Assessment (IOM, 2000).
This approach is appropriate for nutrients with symmetrical requirement
distributions, which is thought to be true for all macronutrients in this
report for which EARs have been established. The following data are
required:

939
A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
â¢ individualâs mean nutrient intake over a given number of days
â¢ day-to-day standard deviation (SD) of intakes for each nutrient of
interest, as estimated from larger data sets for the appropriate life stage
and gender group
â¢ EAR
â¢ SD of the nutrient requirement in the individualâs life stage and
gender group.
From this information a ratio is computed that compares the magnitude
of difference between the individualâs intake and the EAR to an estimate
of variability of intake and requirements. The bigger the difference between
intake and EAR and the lower the variability of intakes and requirements,
the greater is the degree of certainty in assessing whether the individualâs
nutrient intake is adequate, inadequate, or excessive. This approach is
quantitative and should be used only when the data listed above are available.
However, in the more common situation where the estimate of usual
intake is not based on actual 24-hour recalls or records, but on dietary
history or food frequency questionnaires, a qualitative interpretation of
intakes can be used. For example, many practitioners use the diet history
method to construct a likely usual dayâs intake, but the error structure
associated with this method is unknown. While the error associated with
food frequency questionnaires has been evaluated (Carroll et al., 1996;
Liu, 1994), use of these tools for quantitative nutrient assessment is still
not possible due to lack of accurate portion size estimates and grouping of
food items (IOM, 2000). Thus, a practitioner should be cautious when
using this method to approximate usual intakes.
Users of the DRIs may find it useful to consider that observed intakes
below the EAR probably need to be improved (because the probability of
adequacy is 50 percent or less) and those between the EAR and the Recom-
mended Dietary Allowance (RDA) probably need to be improved (because
the probability of adequacy is less than 97 to 98 percent). Only if intakes
have been observed for a large number of days and are at the RDA, or
observed intakes for fewer days are well above the RDA, should one have a
high level of confidence that the intake is adequate. Such considerations
are not applicable in the case of energy intake, which should match energy
expenditure in individuals maintaining desirable body weight (see later
section, âPlanning Nutrient Intakes of Individuals,â and Chapter 5).
Using the Adequate Intake
Adequate Intakes (AIs) have been set for infants younger than 7 months
of age for n-3 and n-6 polyunsaturated fatty acids and protein. By defini-
tion, infants born at term who are exclusively fed human milk by healthy

940 DIETARY REFERENCE INTAKES
mothers consume an adequate nutrient intake. Infants who consume
formulas with a nutrient profile similar to human milk (after adjustment
for differences in bioavailability) are also assumed to consume adequate
levels of nutrients. When an infant formula contains nutrient levels that
are lower than those found in human milk, the likelihood of nutrient
adequacy for infants who consume this formula cannot be determined
because data on infants fed lower concentrations of nutrients are not avail-
able. AIs have also been established for infants 7 to 12 months of age for
all nutrients covered in this report except protein, and for all individuals
for Total Fiber and the n-3 and n-6 polyunsaturated fatty acids.
Equations that can be used to estimate the degree of confidence that
an individualâs usual intake meets or exceeds the AI are presented (IOM,
2000). The data required include the individualâs reported intake over a
given number of days, the AI for the age/gender group, and the day-to-
day (within-person) SD for the nutrient of interest, as estimated from
larger data sets for the appropriate life stage and gender group. Usual
individual intakes that are equal to or above the AI can be assumed to be
adequate. However, the likelihood of inadequacy of usual intakes below
the AI cannot be determined.
Using the Tolerable Upper Intake Level
The Tolerable Upper Intake Level (UL) is used to examine the possi-
bility of over-consumption of a nutrient. Equations have been developed
to determine the degree of confidence that an individualâs intake is below
the UL (IOM, 2000). If an individualâs usual nutrient intake remains below
the UL, there is no risk of adverse effects from excessive intake. At intakes
above the UL, the potential for risk of adverse effects increases. However,
the intake at which a given individual will develop adverse effects as a
result of taking large amounts of one or more nutrients is not known with
certainty. No ULs were set for the macronutrients in this report. However,
there is no established benefit to almost all healthy individuals who con-
sume amounts of nutrients that exceed the RDA or AI.
Equations that can be used to estimate the degree of confidence that
an individualâs usual intake equals or exceeds the UL are presented in
Dietary Reference Intakes: Applications in Dietary Assessment (IOM, 2000). The
data required include the individualâs reported intake over a given number
of days, the UL for the life stage and gender group, and the day-to-day
(within-person) SD for the nutrient of interest, as estimated from larger
data sets for the appropriate life stage and gender group.

941
A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
Using the Acceptable Macronutrient Distribution Range
In addition to presenting DRIs for macronutrients, this report also
presents Acceptable Macronutrient Distribution Ranges (AMDRs) for indi-
viduals as a proportion of total energy intake. The AMDRs represent
intakes that minimize the potential for chronic disease over the long-term,
permit essential nutrients to be consumed at adequate levels, and should
be associated with adequate energy intake and physical activity to maintain
energy balance. The AMDRs for adults are 20 to 35 percent of energy from
fat (including 0.6 to 1.2 percent of energy from n-3 polyunsaturated fatty
acids and 5 to 10 percent of energy from n-6 polyunsaturated fatty acids),
45 to 65 percent of energy from carbohydrate, and 10 to 35 percent of
energy from protein. For children, the AMDRs for total fat are 30 to 40 per-
cent between the ages of 1 and 3 years, and 25 to 35 percent between the
ages of 4 and 18 years. AMDRs for protein and carbohydrate do not vary
with age.
To estimate the degree of confidence that an individualâs diet falls
within the AMDR, the equations developed could be used to estimate the
degree of confidence that the individualâs intake exceeds the AI or remains
below the UL (IOM, 2000). The equation for the AI could be used to
determine the degree of confidence that intake is above the lower end of
the AMDR, and the equation for the UL could be used to determine the
degree of confidence that intake is below the upper end of the AMDR.
The data required include the individualâs average intake of the macro-
nutrient of interest as a percent of energy intake over a given number of
days, the boundaries of the AMDR, and the day-to-day (within-person) SD
of percent energy intake, as estimated from larger data sets for the appro-
priate life stage and gender group.
ASSESSING NUTRIENT INTAKES OF GROUPS
The assessment of nutrient adequacy for groups of people requires
unbiased, quantitative information on the intake of the nutrient of interest
by individuals in the group. Care must be taken to ensure the quality of
the information upon which assessments are made so that they are not
underestimates or overestimates of total nutrient intake. Estimates of total
nutrient intake, including amounts from supplements, should be obtained.
It is also important to use appropriate food composition tables with accu-
rate nutrient values for the foods as consumed.
Several steps must be taken to assess the intake of a group. First, the
intake distribution must be adjusted to remove the effect of day-to-day
variation of individual intake. This can be accomplished either by collect-

942 DIETARY REFERENCE INTAKES
FIGURE 13-2 Comparison of 1-day and usual intakes for estimating the propor-
tion of a group consuming below the Estimated Average Requirement (EAR).
ing dietary data for each individual over a large number of days or by
statistical adjustments to the intake distribution. The statistical adjustments
are based on assumptions about the day-to-day variation derived from
repeat measurements of a representative subset of the group under study
(Nusser et al., 1996). When this adjustment is performed and observed
intakes are thus more representative of the usual diet, the intake distribu-
tion narrows, giving a more precise estimate of the proportion of the group
with usual intakes below requirements (Figure 13-2). An explanation of
this adjustment procedure has been presented in two previous reports
(IOM, 2000; NRC, 1986).
A statistical approach is then used to combine the information on
nutrient intakes with the information on nutrient requirements in order
to determine the apparent percent prevalence of nutrient inadequacy in
the group. Two approaches are briefly described below and in detail else-
where (IOM, 2000; NRC, 1986).
The Probability Approach
Using the probability approach requires knowledge of both the distri-
bution of requirements and the distribution of usual intakes for the popu-
lation of interest. As described previously (IOM, 2000; NRC, 1986), the
probability approach involves: (1) determining the risk of inadequacy for

943
A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
each individual in the population and then (2) averaging the individual
probabilities of inadequacy across the group. Appendix C of Dietary Refer-
ence Intakes: Applications in Dietary Assessment (IOM, 2000) demonstrates
how to carry out the necessary calculations to obtain a prevalence estimate
for a group. Statistical programs (e.g., SAS or similar software) can be used
to carry out these procedures.
The EAR Cut-Point Method
In most situations a cut-point method using the Estimated Average
Requirement (EAR) may be used to estimate the prevalence of inadequate
intakes. This cut-point method is a simplification of the full probability
approach of calculating the prevalence of inadequacy described by the
National Research Council (NRC, 1986). The cut-point method allows the
prevalence of inadequate intakes in a population to be approximated by
determining the percentage of individuals in the group whose usual intakes
are less than the EAR for the nutrient of interest. This method assumes
that the intake and requirement distributions are independent, an assump-
tion that is not valid for the energy requirements addressed in this report
because energy intakes are highly correlated to energy expenditure. The
cut-point method further assumes that the variability of intakes among
individuals within the group under study is at least as large as the variability
of their requirements. This assumption is usually warranted in free-living
populations. Finally, it assumes that the requirement distribution is sym-
metrical. This is thought to be true for all of the macronutrients discussed
in this report.
Using the Estimated Average Requirement
If the assumptions for the EAR cut-point method are met, the preva-
lence of inadequate intakes may be estimated by the proportion of the
distribution of usual intakes that falls below the EAR. An example of using
the EAR cut-point method to assess the dietary carbohydrate adequacy of
women aged 31 to 50 years follows. Dietary intake data are available from
the 1994â1996 Continuing Survey of Food Intakes by Individuals. Esti-
mated intakes are based on respondentsâ intakes, which were adjusted to
remove within-person variability using the Iowa State University method
(Appendix Table E-2). The EAR for women in this age group is 100 g/day.
Examination of the distribution of usual carbohydrate intake reveals that
intakes at the 1st and 5th percentiles are 87 and 118 g/day, respectively.
Thus, fewer than 5 percent of women in this age group appear to have
inadequate carbohydrate intakes.

944 DIETARY REFERENCE INTAKES
Overestimates of the prevalence of inadequate intakes could result if
the data used are based on intakes that are systematically underreported
or if foods rich in the nutrient of interest are underreported. Such under-
reporting is common in national surveys (Briefel et al., 1997). Currently, a
method for adjusting intakes to compensate for underreporting by indi-
viduals is not available, and much work is needed to develop an acceptable
method. Conversely, underestimates of the prevalence of inadequacy could
result if foods rich in the nutrient of interest were overreported. A more
extensive discussion of potential sources of error in self-reported dietary
data can be found in the report Dietary Reference Intakes: Applications in
Dietary Assessment (IOM, 2000).
Comparison of Assessments Using the Probability Approach and
Biochemical Assessment
If requirement estimates are correct, dietary intake data are reliable
estimates of true usual intake, and biochemical measures reflect the same
functional criterion used to set the requirement of a nutrient for the same
population, then the prevalence of apparently inadequate dietary intakes
and biochemical deficiencies or indicators of inadequacy should be similar.
Using the Recommended Dietary Allowance
The Recommended Dietary Allowances are not useful in estimating
the prevalence of inadequate intakes for groups. As described above, the
EAR should be used for this purpose.
Using the Adequate Intake
In this report Adequate Intakes (AIs) are assigned for all nutrients for
infants through the age of 6 months and reflect the average intake of
infants receiving human milk. Human milk and formulas with the same
nutrient composition as human milk (after adjustment for bioavailability)
provide the appropriate levels of nutrients for full-term infants of healthy,
well-nourished mothers. For infants ages 7 to 12 months, AIs are set for
carbohydrate and n-3 and n-6 polyunsaturated fatty acids and reflect the
average intakes of infants receiving human milk and complementary foods.
Groups of infants consuming formulas with lower levels of nutrients than
that found in human milk may be at some risk of inadequacy, although
the prevalence of inadequacy cannot be quantified.
This report provides AIs for all life stage and gender groups for Total
Fiber and n-3 and n-6 polyunsaturated fatty acids. Groups with median
intakes equal to or above the AI for Total Fiber and n-3 and n-6 poly-

945
A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
unsaturated fatty acids can be assumed to have a low prevalence of inade-
quacy (provided that intake variability does not exceed that of the healthy
group used to establish the AI). However, when the AI is not set as a mean
intake of a healthy group (e.g., fiber), confidence in this assessment should
be less than it would be if the AI represents the median intake of a healthy
group. It is important to note that group median intakes below the AI
cannot be assumed to be inadequate.
Using the Tolerable Upper Intake Level
The proportion of the population with usual intakes below the Toler-
able Upper Intake Level (UL) is likely to be at no risk of adverse effects
due to overconsumption. However, the proportion of the population con-
suming above the UL may potentially be at some risk.
The mean intake of a population cannot be used to evaluate the preva-
lence of intakes above the UL. A distribution of usual intakes, including
intakes from supplements, is required to assess the proportion of the popu-
lation that might be at risk of over-consumption. However, if the mean or
median intake is equal to or greater than the UL, it suggests that the
number of individuals with excessive intake is high and warrants further
investigation.
Using the Acceptable Macronutrient Distribution Range
Although primarily directed at individuals, the Acceptable Macronutrient
Distribution Range (AMDR) also permits assessment of populations. By
determining the proportion of the group that falls below, within, and
above the AMDR, it is possible to assess population adherence to recom-
mendations and to determine the proportion of the population that is
outside the range. If significant proportions of the population fall outside
the range, concern could be heightened for possible adverse consequences.
Planning and public health messages can then be instituted to attempt to
attain a low prevalence of intakes below or above the AMDR.
For example, the AMDR for total fat intake of children 4 to 18 years of
age is 25 to 35 percent of energy. Appendix Table E-6 presents data on the
usual daily intake of total fat as a percentage of energy intake and indi-
cates that for all groups of children and adolescents, the 5th percentile of
intake is at least 25 percent. Thus, fewer than 5 percent of children have
intakes below the AMDR for total fat. The 75th percentiles of intake are
close to 35 percent, suggesting that approximately 25 percent of children
and adolescents have intakes above the AMDR for total fat. Intakes of the
remaining 70 to 75 percent fall within the AMDR.

946 DIETARY REFERENCE INTAKES
PLANNING NUTRIENT INTAKES OF INDIVIDUALS
Using the Recommended Dietary Allowance
Individuals should use the Recommended Dietary Allowance (RDA)
as the target for their intakes for those nutrients for which RDAs have
been established. Intakes at this level ensure that the risk to individuals of
not meeting their requirements is very low (2 to 3 percent). For example,
the RDA for protein for adults is 0.8 g/kg/day, or 56 and 46 g/day for
reference men and women weighing 70 kg and 57 kg, respectively. For a
small adult weighing 45 kg, the recommended protein intake would be
36 g/day, while for a larger adult weighing 90 kg, the RDA would be
72 g/day.
Using the Adequate Intake
Adequate Intakes (AIs) are set for infants younger than 7 months of
age for all nutrients, and for all nutrients except protein and indispens-
able amino acids for infants 7 through 12 months of age. Human milk, by
definition, supplies the AI for a nutrient for term infants; it is not neces-
sary to plan additional sources of intake for infants exclusively fed human
milk. Likewise, an infant formula with a nutrient profile similar to human
milk (after adjustment for differences in bioavailability) should supply
adequate nutrients for an infant.
In this report AIs are also set for children, adolescents, and adults for
Total Fiber and n-3 and n-6 polyunsaturated fatty acids. Accordingly, indi-
viduals should use the AI as their goal for intake of these nutrients.
Using the Tolerable Upper Intake Level
Tolerable Upper Intake Levels (Uls) were not set for the macronutrients
covered in this report.
Using the Acceptable Macronutrient Distribution Range
In addition to meeting the RDA or AI and remaining below the UL,
an individualâs intake of macronutrients should be planned so that carbo-
hydrate, total fat, n-3 and n-6 polyunsaturated fatty acids, and protein are
within their respective Acceptable Macronutrient Distribution Ranges.

947
A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
PLANNING NUTRIENT INTAKES OF GROUPS
Using the Estimated Average Requirement and the
Tolerable Upper Intake Level
For those nutrients with Estimated Average Requirements (EAR), the
EAR may be used as a basis for planning or making recommendations for
the nutrient intakes of groups. The mean intake of a group should be high
enough so that only a small percentage of the group would have intakes
below the EAR, thus indicating a low prevalence of dietary inadequacy.
The approach to planning for a low prevalence of inadequacy differs
depending on whether or not the distributions of intake and requirements
are normally distributed. Additional details are provided in the forth-
coming Institute of Medicine report on dietary planning.
For example, assume that the goal of planning was to target a 2 to
3 percent prevalence of inadequacy for a nutrient for which both require-
ment and intake distributions were statistically normal. This would be
attained by planning a group mean intake equal to the EAR plus 2 stan-
dard deviations (SD) of the intake distribution. Because the variability of
intakes generally exceeds the variability of requirements, this target group
mean intake will usually exceed the Recommended Dietary Allowance
(which equals the EAR plus 2 SDs of the requirement distribution). Preva-
lence of inadequacy more or less than 2 to 3 percent could also be consid-
ered. Mean intakes needed to attain the desired prevalence would be
estimated by determining the number of SDs of intake added to the EAR
that would result in the desired percentage prevalence below the EAR.
This can be done by consulting tables that list areas under the curve of the
standard normal distribution in relation to SD scores (z-scores).
When the distribution of intakes is skewed (as is true for intakes of
most nutrients), a low prevalence of inadequacy can be attained by plan-
ning to position the intake distribution such that only the targeted propor-
tion is below the EAR. Finally, when it is known that requirements for a
nutrient are not normally distributed and one wants to ensure a low group
prevalence of inadequacy, it is necessary to examine both the intake and
requirement distributions to determine a median intake at which the pro-
portion of individuals with intakes below requirements is likely to be low.
In addition to planning for an acceptably low group prevalence of
intakes below the EAR, the planned distribution also needs to be examined
to ensure that the prevalence of intakes above the Tolerable Upper Intake
Level (UL) is also acceptably low.
Using the EAR and UL in planning intakes of groups involves the
analysis of data and a number of key considerations such as:

948 DIETARY REFERENCE INTAKES
â¢ determination of the current usual nutrient intake distribution of
the group of interest expressed in the same unit as the EAR (e.g., g/day,
g/kg/day, percent of energy);
â¢ selection of the degree of risk that can be tolerated when planning
for the group (e.g., a 2 to 3 percent prevalence versus a higher or lower
prevalence); and
â¢ consideration of various possible interventions to shift the current
distribution, if necessary, to produce an acceptably low prevalence of
intakes below the EAR, as well as an acceptably low prevalence of intakes
above the UL; some targeted interventions may increase the intake of only
those most at risk, while other interventions (e.g., fortification of the food
supply) may increase the intake, to varying degrees, of the majority of the
population.
Using the Adequate Intake in Planning for Groups
As indicated previously, Adequate Intakes (AIs) have been established
for some of the nutrients discussed in this report. Planning a median group
intake that meets the AI should, by definition, be associated with a low
prevalence of inadequacy, if the AI was set as the median intake of a healthy
group and the group being planned for has similar characteristics to the
group used to establish the AI. If the AI was not set as the median intake of
a healthy group (e.g., the AI for Total Fiber), there is less confidence that
the prevalence of inadequacy would be low if the groupâs median intake
met the AI.
Using the Acceptable Macronutrient Distribution Range
In addition to ensuring that the group prevalence of intakes below the
EAR or above the UL is acceptably low, an additional goal of planning is to
achieve a macronutrient distribution in which the intakes of most of the
group fall within the Acceptable Macronutrient Distribution Ranges
(AMDRs). There may be a tendency for planners to develop menus and
patterns in which the mean population intakes are at the midpoint of the
AMDRs; this is one method to plan for low prevalence of intakes below or
above the AMDR. For example, a meal program for a university dormitory
might be planned using the midpoint of the ranges for carbohydrate and
fat (for adults, these would be 55 and 28 percent of energy, respectively).
The remaining 17 percent of energy would come from protein. Assess-
ment would be needed to determine whether intakes of most members of
the group fell within the AMDR, or whether interventions were required
to target one end of the distribution (e.g., those with fat intakes above
35 percent). However, planning for the midpoint of a range is not the

949
A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
only way that the AMDR can be used to plan for groups. Using the univer-
sity dormitory example, a dietary pattern might be planned in which the
mean intake from fat was 30 percent of energy. Assessment conducted
following implementation of the program might reveal that actual fat
intakes of the students ranged from about 25 percent to about 35 percent
of energy. In other words, the prevalence of intakes outside the acceptable
range is low, despite a mean fat intake that is higher than the midpoint of
the range. While the AMDR can be used as a general quantitative guide-
line for planning and evaluating diets, qualitative considerations, such as a
menu low in saturated fats, may be at least as important as these quantita-
tive guidelines (see Chapter 11).
NUTRIENT-SPECIFIC CONSIDERATIONS
Energy
Planning Energy Intakes for Individuals
The underlying objective of planning for energy is similar to planning
for nutrientsâto attain an acceptably low risk of inadequacy and of excess.
The approach to planning for energy, however, differs substantially from
planning for other nutrients. When planning for an individualâs intake of
nutrient such as vitamins and minerals, the goal is a low risk of inadequacy
by meeting the Recommended Dietary Allowance (RDA) or Adequate
Intake (AI), and a low risk of excess by remaining below the Tolerable
Upper Intake Level (UL). Even though intakes at or above the RDA or AI
are almost certainly above an individualâs requirement, there are no
adverse effects to the individual of consuming an intake above his or her
requirement, provided intake remains below the UL; however there are
also no documented benefits.
The situation for energy is quite different. There are adverse effects to
individuals who consume energy above their requirementsâover time,
weight gain will occur. This difference is reflected in the fact that there is
no RDA for energy, as it would be inappropriate to recommend an intake
that exceeded the requirement (and would lead to weight gain) of 97 to
98 percent of individuals. The requirement for energy for individuals of
normal weight is expressed as an Estimated Energy Requirement (EER),
which reflects the energy expenditure associated with an individualâs sex,
age, height, weight, and physical activity level.
Equations are presented to estimate an individualâs energy expendi-
ture, with separate equations for normal (body mass index [BMI] > 18.5
and < 25) and overweight (BMI â¥ 25) individuals, as well as for all individuals
with BMI > 18.5 (i.e., including normal, overweight, and obese subjects).

950 DIETARY REFERENCE INTAKES
For overweight individuals, these equations estimate Total Energy Expen-
diture (TEE), rather than the EER, which is reserved for normal weight
individuals. In all cases, however, the equations estimate the energy expen-
diture associated with maintaining current body weight and activity level.
They were not developed, for example, to lead to weight loss in overweight
individuals. However, just as is the case with other nutrients, energy expen-
ditures vary from one individual to another, even though their characteris-
tics may be similar. This variability is reflected in the standard deviation
(SD), which allows for estimation of the range within which the individualâs
energy expenditure could vary. Note that this does not imply that an indi-
vidual would maintain energy balance at any intake within this range; it
simply indicates how variable requirements could be among those with
similar characteristics.
For example, the equation for the EER of women ages 19 years and
older with a BMI > 18.5 and < 25 is:
Energy (kcal) = 354.1 â (6.91 Ã age [y]) + physical activity coefficient
Ã (9.36 Ã weight [kg] + 726 Ã height [m])
The SD is 160 kcal. Therefore, the EER for a normal-weight, 33-year-old
low-active woman (i.e., with a physical activity level (PAL) between 1.4 and
1.59, for whom the physical activity coefficient is 1.12), with a height of
1.63 m and a weight of 55 kg would be:
Energy (kcal) = 354.1 â (6.91 Ã 33) + 1.12
Ã (9.36 Ã 55 + 726 Ã 1.63) = 2,028
The 95 percent confidence interval for this equation reflects the range
within which a given individualâs energy expenditure likely falls, and in
this example, it would be 2,028 Â± (2 Ã 160), or between 1,708 and
2,348 kcal/day. It must be realized that considerable uncertainties are
inherent in making such predictions, notably because of possible mis-
classification of individuals into the various PAL categories (i.e., sedentary,
low active, active, and very active).
Usual energy intakes are highly correlated with expenditure when con-
sidered over periods of weeks or months. This means that most people
who have access to enough food will, on average, consume amounts of
energy very close to the amounts that they expend, and as a result, main-
tain their weight over extended periods of time. Any changes in weight
that do occur usually reflect small imbalances accumulated over a long
period of time. For normal individuals who are weight-stable, at a healthy
weight, and performing at least the minimal recommended amount of
activity, their energy requirement (and recommended intake) is their usual

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A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
energy intake. Thus, if an individualâs usual energy intake were known, the
plan would be to maintain it rather than use the EER (or if overweight, the
TEE). In many situations, however, the usual energy intake of an indi-
vidual is not known, and the estimated energy requirement equations are
useful planning tools.
Using the EER (or TEE) to Maintain Body Weight. When the goal is to
maintain body weight in an individual with specified characteristics (age,
height, weight, and activity level), an initial estimate for energy intake is
provided by the equation for the energy expenditure of an individual with
those characteristics. By definition, the estimate would be expected to
underestimate the true energy expenditure 50 percent of the time and to
overestimate it 50 percent of the time, leading to corresponding changes
in body weight. This indicates that monitoring of body weight would be
required when implementing intakes based on the equations that predict
individual energy requirements. For example, if subjects were enrolled in
a study in which it was important to maintain body weight, each individual
would be fed the amount of energy estimated to be needed based on the
EER equation. Body weight would be closely monitored over time, and the
amount of energy provided to each individual would be adjusted up or
down from the EER (or TEE) as required to maintain body weight.
Using the EER (or TEE) to Plan to Prevent Weight Loss. In some situa-
tions the goal of planning might be to prevent weight loss in an individual
with specified characteristics. In this situation, the EER or TEE equation
could be used to derive the average energy expenditure for the individual,
and then an amount equal to two times the SD added. This would lead to
an intake that would be expected to exceed the actual energy expenditure
of all but 2 to 3 percent of the individuals with similar characteristics.
Using the above example for the 33-year-old, low-active woman, one would
provide 2,028 + (2 Ã 160) kcal, or 2,348 kcal. This intake would prevent
weight loss in almost all individuals with similar characteristics. Of course,
this level of intake would lead to weight gain in most of these individuals.
Using the EER (or TEE) to Plan to Prevent Weight Gain. If the goal of
planning is to prevent weight gain in an individual with specified charac-
teristics, the appropriate EER equation could be used to derive the aver-
age energy expenditure for the individual, and then subtract an amount
equal to two times the SD. This would lead to an intake that would be
expected to fall below the actual energy requirements of all but 2.5 per-
cent of the individuals with similar characteristics. Using the above
example for the 33-year-old, low-active woman, the energy requirement
would be 2,028 â (2 Ã 160) kcal, or 1,708 kcal. This intake would prevent

952 DIETARY REFERENCE INTAKES
weight gain in almost all individuals with similar characteristics. Of course,
this level of intake would lead to weight loss in most of these individuals.
Planning for Energy for Groups
As is true for individuals, the underlying objective in planning the
energy intake of a group is similar to planning intakes for other nutrientsâ
to attain an acceptably low prevalence of inadequacy and of potential
excess. The approach to planning for energy, however, differs substan-
tially from planning for other nutrients. When the Estimated Average
Requirement (EAR) cut-point method is used to plan for a groupâs intake
of nutrients such as vitamins and minerals, a low prevalence of inadequacy
is obtained by positioning the intake distribution such that an acceptably
low proportion of the group has an intake below the EAR. A low preva-
lence of potential risk of excess is obtained by positioning the intake distri-
bution such that an acceptably low proportion of the group has an intake
above the UL. Even though the planned distribution of intakes would
exceed the actual requirements of all but the designated proportion of the
group (in many cases, by a considerable margin), there are no known
adverse effects to the group of consuming vitamins and minerals in amounts
that exceed requirements, provided the proportion above the UL also
remains low.
In the case of energy, however, there are adverse effects for the indi-
viduals in the group whose intakes are above their requirements, as weight
gain is bound to occur over time. Therefore, the EAR cut-point method to
plan for group intakes of energy is clearly inappropriate. In addition, the
assumptions required to apply this method, as well as for the probability
approach, do not hold for energy. Most notably, the methods assume that
intakes are essentially uncorrelated with requirements. In the case of
energy, however, intakes are very highly correlated with requirements.
What, then, can be done to plan for energy intakes of groups? There
are two possible approaches: estimate energy requirements for the refer-
ence person or obtain an average of estimated maintenance energy needs
for group members.
Estimate Energy Requirements for the Reference Person. One approach is
to use the EER for the reference person who represents the group. For
example, to plan for a large group of men ages 19 to 30 years, estimate the
EER for the reference male with a weight of 70 kg and a height of 1.76 m
and who is considered low active, and use this number (~2,700 kcal) as the
target for the group. This approach would require the assumption that all
members of the group were similar to the reference person, or that the
reference individual accurately represented group average values for age,

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A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
height, weight, and activity level, and that these variables were symmetrically
distributed. If either assumption held, the resulting EER would approxi-
mate the group mean energy requirement.
However, if the assumptions did not hold true, as is likely in many
situations, the estimates would be incorrect. At a practical level, it is likely
that the estimate obtained would be less than the true average energy
expenditure of the group, since for most life stage and gender groups the
reference person weighs less than the average person.
Obtain an Average of Estimated Maintenance Energy Needs for Group
Members. The preferred approach would be to plan for an intake equal to
the average energy expenditure for the group. For example, using the
same group of 19- to 30-year-old men from the previous section, the energy
expenditure for each individual in the group would be estimated (assum-
ing access to data on height, weight, age, and activity level). The average of
these values would be used as the planning goal for maintenance of current
weight and activity level. Table 13-1 shows an example of how this is done
for a small group of six healthy men with a BMI < 25. If the group included
men with a BMI > 25, the equations developed to estimate the Total Energy
Expenditure for overweight individuals would be used for those individuals
with BMI > 25.
In this hypothetical example, the average planned intake exceeds the
EER of five of the men, and is below the EER of one large, very active man
(in a larger, more homogeneous group, the estimate would be expected to
TABLE 13-1 Obtaining an Average Estimated Energy
Requirement (EER) for a Group
Physical
Physical Activity
EERa
Age Height Weight Activity Level
Subject (y) (m) (kg) Level Coefficient (kcal)
1 21 1.83 95 Sedentary 1.0 2,961
2 27 1.77 75 Low active 1.12 2,811
3 25 1.69 60 Active 1.27 2,794
4 19 1.80 75 Low active 1.12 2,905
5 30 1.73 80 Very active 1.45 3,575
6 25 1.75 75 Low active 1.12 2,818
Mean 24.5 1.76 76.7 â 1.18 2,977
a Energy (kcal) = 661.8 â 9.53 Ã age (y) + physical activity coefficient Ã [15.91 Ã weight
(kg) + 539.6 Ã height (m)]. Physical activity level coefficient = 1.0 (sedentary), 1.12
(active), 1.45 (very active).

954 DIETARY REFERENCE INTAKES
be inadequate for half the men and above the requirement for the other
half). However, because intakes and expenditures are highly correlated,
and assuming that all members of the group have free access to food, most
members of the group will consume an amount of energy equal to their
expenditure. Thus, planning for an intake that approximates the mean
energy expenditure should allow the group to meet energy needs for
weight maintenance and current activity levels.
Caveats. As with other planning applications, it should be emphasized
that the planning goal is for energy intakes. The above approach requires
the assumption that free access to food is available, that each member of
the group consumes an amount of energy that approximates their indi-
vidual expenditure, and that food is not wasted or spoiled. As with other
planning examples, food waste and to what extent the amount of energy
offered would need to exceed the target median intake need to be consid-
ered. Assessing the plan following its implementation would lead to further
refinements.
Assessing Energy Intakes
As was true for planning, the approach to assessing the adequacy of
energy intakes differs from that described for other nutrients. This arises
in part from theoretical considerations. Perhaps more importantly though,
it is related to the fact that for energy, unlike most nutrients, a readily
observable, accurate biological indicatorâbody weightâcan be used to
assess the long-term adequacy of energy intake. An individual or group
with a BMI above the desirable range reflects long-term excess energy
intake, while the converse is true when BMI is below the desirable range.
The availability of a biological indicator to assess the adequacy of
energy intake becomes particularly critical because of the effect of dietary
underreporting on the assessment of adequacy. It is now widely accepted,
and supported by a large body of literature, that underreporting of food
intake is pervasive in dietary surveys (Black et al., 1993). Underreporters
can constitute anywhere from 10 to 45 percent of the total sample, depend-
ing on the age, gender, and body composition of the sample. Under-
reporting tends to increase in prevalence as children age (Livingstone et
al., 1992), and is greater among women than among men (Johnson et al.,
1994). Both the prevalence and severity of underreporting is greater among
obese individuals compared with lean individuals (Bandini et al., 1999;
Lichtman et al., 1992; Prentice et al., 1986). In addition, those of low
socioeconomic status (characterized by low incomes, low educational
attainment, and low literacy levels) are more likely to report low energy
intakes (Johnson et al., 1998; Kristal et al., 1997; Pryer et al., 1997). There-

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A PPLICATIONS OF DRIs FOR MACRONUTRIENTS
fore, self-reported energy intakes do not reflect actual energy intakes, and
other methods must be used to determine their adequacy. Relative body
weight (as reflected by BMI) is a preferred indicator of energy adequacy
for individuals and for groups.
Assessing Adequacy of Energy Intakes of Individuals. Theoretically, one
could compare the usual energy intake of an individual to his or her
requirement to maintain current weight and activity level, as estimated
using the equations developed to estimate energy expenditure. However,
as noted above, the EER (or TEE) equation provides an estimate that is
the midpoint of the range within which the expenditure of an individual
with specified characteristics could vary, and the individualâs actual expen-
diture could be considerably above or below the midpoint. Accordingly,
comparing the individualâs intake to the calculated average expenditure is
essentially meaningless. For example, the EER for a 33-year-old, low-active
woman with a height of 1.63 m and a weight of 55 kg would be calculated
at 2,028 kcal, but expenditure for a woman with these characteristics could
vary between 1,708 and 2,348 kcal. If the womanâs actual energy intake
averaged 2,200 kcal, her actual intake could be inadequate, adequate, or
excessive.
BMI, in contrast, provides a useful indicator of the adequacy of usual
energy intake in relation to usual energy expenditure. If the woman in the
above example had a BMI of 22 (i.e., within the healthy range of > 18.5
and < 25), her usual energy intake would be assessed as adequate relative
to her usual expenditure. If her BMI was 17 (below the healthy range),
then she would be assessed as having an inadequate energy intake; if it was
33 (above the healthy range), her intake would be assessed as excessive.
Assessing Adequacy of Energy Intakes of Groups. Instead of assessing the
adequacy of energy intake by comparing reported intakes (which are almost
always affected by considerable underreporting) to estimated expenditure,
relying on BMI as a biological indicator is preferable. The distribution of
BMI within a population group can be assessed, and the proportions of
the group with BMI below, within, and above the desirable range would
reflect the proportions with inadequate, adequate, and excessive energy
intakes. When this approach is applied to body-weight data of adults ages
19 to 50 years obtained in the Continuing Survey of Food Intakes by
Individuals, 59 percent of men and 44 percent of women are found to
have a BMI â¥ 25, reflecting excessive energy intake; 40 percent of men and
52 percent of women have a BMI within the ideal range, reflecting ade-
quacy; and 0.9 percent of men and 4.6 percent of women have a BMI
below 18.5, reflecting inadequacy.

956 DIETARY REFERENCE INTAKES
Although the above discussion refers to the adequacy of energy intake,
it should be reiterated that intake is just one component of energy balance.
Excessive intake must be interpreted as being excessive in relation to energy
expenditure. In many cases, intake may not be excessive in absolute terms;
instead, inadequate energy expenditure may be the primary factor in con-
tributing to long-term positive energy balance. This has important implica-
tions for how this issue is best addressed at the population level. There are
a number of reasons why increased energy expenditure may be a more
appropriate solution than decreased energy intake to long-term positive
energy balance (i.e., overweight). First, restricting energy intake also
decreases the ability to meet requirements of many nutrients. Second,
evidence exists to support the concept that much of the health risk attrib-
uted to an increased BMI is associated with poor fitness. Increasing physical
activity, thereby improving fitness, improves health outcomes of overweight
individuals irrespective of changes in relative weight (Blair et al., 1993, 1995).
Implications of Underreporting for Other Macronutrients. In addition to
the major impact of underreporting on assessment of the adequacy of
energy intake, it also has potential implications for other macronutrients.
If it is assumed that underreporting of macronutrients occurs in propor-
tion to underreporting of energy intake, macronutrients expressed as a
percentage of energy would be relatively accurate. Accordingly, there
would be little impact on the estimated proportions of those whose intakes
fall outside the Acceptable Macronutrient Distribution Ranges (AMDRs)
for carbohydrate, protein, total fat, and n-3 and n-6 polyunsaturated fatty
acids. Underreporting would, however, overestimate the prevalence of
dietary inadequacy for protein, indispensable amino acids, and carbo-
hydrate. Conversely, it has been suggested that underreporting of nutrients
may not occur in proportion to underreporting of energy (IOM, 2000). If,
for example, fat intake is preferentially underreported, this would lead to
an underestimate of the proportion of those whose intakes are above the
upper end of the AMDRs for total fat and for n-3 and n-6 polyunsaturated
fatty acids. It could also lead to an overestimate of the percentage of energy
derived from carbohydrate.
Total Carbohydrate
The Dietary Reference Intakes (DRIs) for total carbohydrate (starches
and sugars) are set in this report as EARs and RDAs, expressed as absolute
amounts (g/day) that support brain glucose utilization. The RDA for carbo-
hydrate (130 g/day) is an average minimum requirement and is lower
than what most North Americans consume (Appendix Table E-2). A UL is
not established for total carbohydrate. Most people can meet their

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requirement for carbohydrate without difficulty by consuming a varied
diet containing breads, rice, other grain products, potatoes, fruits, vege-
tables, milk products, and (in moderate amounts) starch- or sugar-based
snack foods.
As discussed in Chapter 11, to achieve a healthful balance of the macro-
nutrients that supply energy, the AMDR for total carbohydrate is 45 to
65 percent of energy. This range allows for intakes of carbohydrate that
exceeds the RDA of 130 g/day. The carbohydrate content of most U.S.
diets is either less than or within this range (see Appendix Table E-3), but
it is more likely to be within this range if food selections emphasize grains,
fruits, and vegetables prepared with minimal or modest amounts of fat.
Added Sugars
Added sugars are defined as sugars and syrups that are added to foods
during processing or preparation. Major sources of added sugars include
soft drinks, cakes, cookies, pies, fruitades, fruit punch, dairy desserts, and
candy (USDA/HHS, 2000). Specifically, added sugars include white sugar,
brown sugar, raw sugar, corn syrup, corn-syrup solids, high-fructose corn
syrup, malt syrup, maple syrup, pancake syrup, fructose sweetener, anhydrous
dextrose, and crystal dextrose. Since added sugars provide only energy
when eaten alone and lower nutrient density when added to foods, it is
suggested that added sugars in the diet should not exceed 25 percent of
total energy intake. Usual intakes above this level place an individual at
potential risk of not meeting micronutrient requirements. Nutrient data
on added sugars has only recently become available in the U.S. Depart-
ment of Agricultureâs (USDA) Pyramid Servings Database, which includes
data on added sugars for over 7,000 foods. Appendix Table D-1 describes
the Third National Health and Nutrition Examination Survey (NHANES
III) results on the distribution of intakes of added sugar.
To assess the sugar intakes of groups requires knowledge of the distri-
bution of usual added sugar intake as a percent of energy intake. Once this
is determined, the percentage of the population exceeding the maximum
suggested level can be evaluated. Because the criterion for the suggested
maximum intake level of added sugars is the risk of associated inadequate
intakes of micronutrients, such an evaluation would be complemented by
assessing micronutrient intakes, as described in the DRI report for those
nutrients (IOM, 2001) and the report on dietary assessment (IOM, 2000).
Dietary, Functional, and Total Fiber
Dietary Fiber is defined in this report as nondigestible carbohydrates
and lignin that are intrinsic and intact in plants. Functional Fiber is defined

958 DIETARY REFERENCE INTAKES
as isolated, nondigestible carbohydrates that have beneficial physiological
effects in humans. Total Fiber is the sum of Dietary Fiber and Functional Fiber.
Fiber includes viscous forms that lower serum cholesterol concentrations
(i.e., soluble fiber: oat bran, beans) and the bulking agents that improve
laxation (i.e., insoluble fiber: wheat bran). The AI for Total Fiber is 38 and
25 g/day for 19- to 50-year-old men and women, respectively, based on a
reduced risk of coronary heart disease for those within the highest quintiles
of dietary fiber consumption (g/1,000 kcal) in several epidemiological
studies and the median energy intake (Appendix Table E-1). Unlike the
AI for some nutrients, this AI does not describe the median Total Fiber
intake of a healthy population. Instead, it is based on health benefits asso-
ciated with consuming foods that are rich in fiber. Based on CSFII data
(Appendix Table E-4), the median Dietary Fiber intakes are 16.5 to 17.9 g/day
for men and 12.1 to 13.3 g/day for women. Thus, it is evident that to meet
the AI, most people will need to substantially increase their Total Fiber intake.
Usual intakes that meet or exceed the AI can be assumed adequate, but the
likelihood of inadequacy of usual intakes below the AI cannot be determined.
Fiber consumption can be increased by substituting whole grain or
products with added cereal bran for more refined bakery, cereal, pasta,
and rice products; by choosing whole fruits instead of fruit juices; by con-
suming fruits and vegetables without removing edible membranes or peels;
and by eating more legumes, nuts, and seeds. For example, whole wheat
bread contains three times as much Dietary Fiber as white bread, and the
fiber content of a potato doubles if the peel is consumed. The soluble and
insoluble fiber components of 228 U.S. foods have been published by
Marlett and Cheung (1997).
Dietary fiber data are listed for a wide range of foods in the USDA
Nutrient Database for Standard Reference (USDA, 2001). The dietary fiber
values in the USDA database represent Total Fiber (including both dietary
and functional fiber) as defined in this report. For most diets (those that
have not been fortified with Functional Fiber that was isolated and added for
health purposes), the contribution of Functional Fiber is minor relative to
the naturally occurring Dietary Fiber. For example, the Functional Fiber con-
tent for foods such as fat-free yogurts and ice creams that contain added
guar gums and carrageenan is so low that the USDA database generally
indicates zero dietary fiber for these foods. Although the AI is set for Total
Fiber, this AI is generally based upon the fibers present in foods, and until
these terms are further incorporated into nutrient databases, it is appro-
priate to apply the Dietary Fiber data from the USDA database to the AI for
Total Fiber.
Because there is insufficient evidence of deleterious effects of high
Dietary Fiber as part of an overall healthy diet, a Tolerable Upper Intake
Level has not been established.

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Total Fat and n-3 and n-6 Polyunsaturated Fatty Acids
Total Fat
No RDAs or AIs are set for total fat, but an AMDR of 20 to 35 percent
of energy is recommended for adults (Chapter 11). Thus, when planning
diets for individuals, it is necessary to first calculate the individualâs esti-
mated energy expenditure, determine 20 and 35 percent of this number
in kilocalories, and then divide by 9 kcal/g to get the range of fat intake in
grams per day. For example, a person whose energy expenditure was
2,300 kcal/day should aim for an energy intake from fat of 460 to 805 kcal/
day. In grams of total fat, intake should be between 51 and 89 g/day.
Likewise, when assessing fat intakes of individuals, the goal is to deter-
mine if usual energy intake from total fat is between 20 and 35 percent. As
illustrated above, this is a relatively simple calculation assuming both usual
fat intake and usual energy intake are known. However, because dietary
data are typically based on a small number of days of records or recalls, it
may not be possible to state with confidence that a diet is within this range.
As explained in the DRI dietary assessment report (IOM, 2000), an adjust-
ment can be made for the likelihood that these are not representative
days, based on the day-to-day variation in fat intake and the number of
days of dietary data.
When planning fat intakes for groups, the goal is to minimize the
intakes of total fat that are outside the AMDR of 20 to 35 percent of energy
from fat. If planning is for a confined population, a procedure similar to
the one described for individuals may be used: determine the necessary
energy intake from the planned meals and plan for a fat intake that pro-
vides between 20 and 35 percent of this value. If the group is not confined,
then planning intakes is more complex and ideally begins with knowledge
of the distribution of usual energy intake from fat. Then the distribution
can be examined, and feeding and education programs designed to either
increase, or more likely, decrease the percent of energy from fat.
Assessing the fat intake of a group requires knowledge of the distribution
of usual fat intake as a percent of energy intake. Once the distribution is
described, the percent of the population outside the AMDR can be calcu-
lated. For example, Appendix Table E-6 shows that in the CSFII, less than
1 percent of the population was below 20 percent of energy from fat, while
over 50 percent consumed greater than 35 percent of energy from fat.
n-3 and n-6 Polyunsaturated Fatty Acids
n-3 and n-6 Polyunsaturated fatty acids have an AI based on median
intakes of linoleic acid and Î±-linolenic acid from CFSII, respectively. In
addition to an AI, an AMDR is provided for n-3 and n-6 fatty acids. The

960 DIETARY REFERENCE INTAKES
suggested range is 0.6 to 1.2 percent of energy from n-3 fatty acids and 5 to
10 percent of energy from n-6 fatty acids. Thus, there are several consider-
ations when planning and evaluating n-3 and n-6 fatty acid intakes. Usual
intakes that meet or exceed the AI can be assumed adequate, but the
likelihood of inadequacy of usual intakes below the AI cannot be deter-
mined. Assessing n-3 and n-6 fatty acid intakes of groups against the AMDR
requires knowledge of the distribution of usual fatty acid intake as a per-
centage of energy intake. Once the distribution is described, the percent-
age of the population outside the AMDR can be calculated.
Saturated Fatty Acids, Trans Fatty Acids, and Cholesterol
No RDAs, AIs, or AMDRs are provided for saturated fatty acids, trans
fatty acids, and cholesterol. However, with increasing intakes of either of
these three nutrients, there is an increased risk of coronary heart disease.
Chapter 11 provides some dietary guidance on ways to reduce the intake
of saturated fatty acids, trans fatty acids, and cholesterol. For example,
when planning diets, it is desirable to replace saturated fat with either
monounsaturated or polyunsaturated fats to the greatest extent possible.
Protein and Amino Acids
The EARs and RDAs for protein and amino acids have been expressed
as grams per kilogram per day, the first DRIs to be expressed in this way.
This implies that requirements and recommended intakes vary among indi-
viduals of different sizes, and should be individualized when used for
dietary assessment or planning. The potential implications of this are
discussed below.
Dietary Assessment
For most nutrients for which EARs have been defined, the prevalence
of inadequate intakes can be estimated as the proportion of the distribu-
tion of usual intakes that falls below the EAR using the EAR cut-point
method (IOM, 2000). However, this method requires a number of assump-
tions, including that the individual requirement for the nutrient in
question has a symmetric distribution. As described in Chapter 10, the
distribution of the individual requirement for protein for adults is skewed,
however, this skewing appears to be slight and the EAR cut-point method
is expected to provide a good approximation to prevalence.
However, if more accuracy is needed, the âprobability approachâ can
be used. This approach has been described elsewhere (IOM, 2000; NRC,
1986), and its application for assessing the prevalence of inadequacy of

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iron intakes has been illustrated (IOM, 2002). The probability approach
for assessing the adequacy of protein intakes is identical to that outlined
for iron, with the simplification that percentiles of protein requirement
can be explicitly calculated from the formula given in Chapter 10 (âRDA
Summary, Ages 19â50 Yearsâ).
Planning the Diet
When planning a diet for an individual, recommended intakes can be
determined on the basis of the individualâs body weight. Although the RDA
for the reference adult male is 56 g/day of protein (based on 0.8 g/kg/day
for a 70-kg person), the recommended intakes for men weighing 60 kg
and 90 kg would be 48 and 72 g/day, respectively.
It should be noted that the DRIs are intended to apply to healthy
individuals. Thus, determining a recommended protein intake based on
current body weight may not be appropriate for those who are signifi-
cantly underweight or overweight. For example, a medical professional
might choose to specify a protein intake for a malnourished, underweight
patient based on what the patientâs body weight would be if he were
healthy. A patient weighing 40 kg, whose body weight when healthy was
55 kg, could thus have a recommended protein intake of 44 g/day (55 kg
Ã 0.8 g/kg), rather than the 32 g/day that would be determined based on
current weight. Conversely, protein intakes recommended for individuals
who are morbidly obese could be based on the amounts recommended for
those with more normal body weights.
Are Planning and Assessing Intakes of Indispensable
Amino Acids Necessary?
The previous RDAs and Recommended Nutrient Intakes did not include
recommended intakes for indispensable amino acids; it was assumed that
individuals consuming a mixed diet with recommended amounts of pro-
tein would obtain required amounts of indispensable amino acids. In other
words, it was not necessary to assess or plan for intakes of indispensable
amino acids. Now that EARs and RDAs have been provided for indispens-
able amino acids, it is important to re-examine the question: Is it necessary
to consider indispensable amino acids when conducting dietary planning
and assessment, or is it sufficient to consider only total protein?
The simplest scenario for answering this question relates to dietary
planning for individuals. When planning for individuals, the objective is to
meet the RDA, as doing so ensures a very low risk of inadequacy. Thus, do
diets that provide the RDA for protein also provide the RDAs for indis-
pensable amino acids? It appears that this may not necessarily occur, at

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As alluded to above, the need to plan and assess intakes of lysine is
likely of greatest importance for individuals whose diets emphasize plant
foods and are relatively low in total protein. For example, consider a
woman who weighs 57 kg and follows a plant-based diet that provides the
RDA for total protein (in her case, 57 Ã 0.8 g/kg = 45 g/day). She would
be unlikely to meet her RDA for lysine (2.2 g/day) unless 50 percent or
more of her dietary protein was provided from beans or tofu (rich sources
of lysine). To be specific, 23 g of protein from beans and tofu would
provide about 1.5 g of lysine, and 22 grams of protein from other sources,
such as wheat, rice and nuts, would provide about 0.7 g of lysine. However,
if her total protein intake was higher, (e.g., about 63 g/day, close to the
median protein intake of women reported in the CSFII survey [Appendix
Table E-16]), she could meet her RDA for lysine with much smaller
amounts of beans and tofu.
INTEGRATED EXAMPLE
The preceding discussion illustrates that there are many considerations
involved in dietary assessment and planning for energy and macronutrients.
The example that follows illustrates how these considerations might be
addressed in planning the macronutrient intake of an individual. Let us
assume that the individual is a 35-year-old woman, 1.68 m in height, and
weighing 69 kg. Her job is not physically active, and she does little planned
exercise, so it might appear that activity level would be classified as sedentary.
However, to provide a more reliable indication of her activity level, she
keeps a 7-day record of her activities using a chart similar to that provided
in Chapter 12 (Table 12-3), and this also confirms that she is sedentary.
Energy
Because recommended intakes of at least some nutrients relate to
energy requirements, the first step would be to estimate her energy expen-
diture. Her BMI is 24.4, so the equation for normal-weight adults would be
used. Assuming it was appropriate to maintain her current weight and
activity level, the Estimated Energy Requirement for a woman with her
characteristics would be about 2,000 kcal/day. Of course, her individual
energy expenditure could be above or below this amount, but it provides a
starting point. An additional consideration would be that her current
activity level is less than the recommended of âactive.â If her energy needs
were estimated based on being âactive,â the estimate would be 2,150 kcal,
and other values listed below would change proportionally.

964 DIETARY REFERENCE INTAKES
Fatty Acids
The AI for n-3 polyunsaturated fatty acid (Î±-linolenic acid) is 1.1 g/day,
and the AI for n-6 polyunsaturated fatty acid (linoleic acid) is 12 g/day.
Therefore, her diet should provide these levels of fatty acids, which would
provide 9.9 and 108 kcal/day from n-3 and n-6 fatty acids, respectively,
toward her total energy intake. Longer-chain polyunsaturated n-3 (approxi-
mately 10 percent) and n-6 fatty acids can contribute toward this AI.
Protein
The RDA for protein is 0.8 g/kg/day, so her recommended intake
would be 55 g/day (69 kg Ã 0.8 g/kg), which would provide 220 kcal/day.
In addition, she would need to meet recommended intakes of indispens-
able amino acids, of which lysine is most likely to be limiting. Her recom-
mended lysine intake would be 38 mg/kg/day, or approximately 2.6 g/day.
Carbohydrate and Total Fiber
The RDA for carbohydrate for adult women is 120 g/day, which is
equivalent to 480 kcal/day. More than 120 g/day will probably be needed
to assure adequate energy consumption within the AMDR for carbo-
hydrate. The AI for Total Fiber is 25 g/day and her diet should be planned
to provide for this level of intake. The contribution of Total Fiber to energy
(kcal/g) intake is still unclear.
Energy Distribution
The amount of energy provided by the recommended intakes of es-
sential fatty acids, protein, and carbohydrate totals only 818 kcal/day, yet
her estimated requirement is approximately 2,000 kcal/day. Her energy
intake might be allocated among macronutrients as shown in Table 13-3
for an overall healthy diet.
Because the estimated energy expenditure of 2,000 kcal/day may differ
from actual energy expenditure (and lead to changes in weight that may
not be desirable), her weight should be monitored over time and energy
intake adjusted as appropriate.
SUMMARY
The Dietary Reference Intakes (DRIs) may be used to assess nutrient
intakes as well as to plan nutrient intakes. Box 13-1 summarizes the appro-
priate uses of the DRIs for individuals and groups.

966 DIETARY REFERENCE INTAKES
BOX 13-1
Uses of Dietary Reference Intakes for Healthy Individuals and Groups
For the Individual a For a Group b
Type of Use
EARc: Use to examine the prob-
Assessment EAR: Use to estimate the preva-
ability that usual intake is inad- lence of inadequate intakes
equate. within a group.
RDA: Usual intake at or above RDA: Do not use to assess in-
this level has a low probability takes of groups
of inadequacy.
AId: Mean usual intake at this
AId: Usual intake at or above level implies a low prevalence
this level has a low probability of inadequate intakes.
of inadequacy.
UL: Use to estimate the per-
UL: Intake above this level has centage of the population at
a potential risk of adverse ef- potential risk of adverse effects
fects. from excess nutrient intake.
RDAe : Aim for this intake. EARe: Use to plan an intake dis-
Planning
tribution with a low prevalence
AId: Aim for this intake. of inadequate intakes.
AId: Use to plan mean intakes.
UL: Use as a guide to limit in-
take; chronic intake of higher
amounts may increase the po- UL: Use to plan intake distribu-
tential risk of adverse effects. tions with a low prevalence of
intakes potentially at risk of ad-
verse effects.
a Requires accurate measure of usual intake. Evaluation of true status requires clinical, biochemi-
cal, and anthropometric data.
b Requires statistically valid approximation of distribution of usual intakes.
c Requires information on the variability of day-to-day intake and the variability of the require-
ment.
d For the nutrients in this report, AIs are set for infants for all nutrients, and for other age groups
for Total Fiber and for n-3 and n-6 polyunsaturated fatty acids. The AI may be used as a guide for
infants as it reflects the average intake from human milk. Infants consuming formulas with the
same nutrient composition as human milk consume an adequate amount after adjustments are
made for differences in bioavailability. In the context of assessing groups, when the AI for a
nutrient is not based on mean intakes of a healthy population, this assessment is made with less
confidence.
e In the case of energy, an Estimated Energy Requirement (EER) is provided; it is the dietary
energy intake that is predicted (with variance) to maintain energy balance in a healthy adult of
defined age, gender, weight, height, and level of physical activity, consistent with good health. In
children and pregnant and lactating women, the EER is taken to include the needs associated with
the deposition of tissues or the secretion of milk at rates consistent with good health. For individu-
als, the EER represents the midpoint of a range within which an individualâs energy requirement is
likely to vary. As such, it is below the needs of half the individuals with specified characteristics and
exceeds the needs of the other half. Body weight should be monitored and energy intake adjusted
accordingly.
NOTE: RDA = Recommended Dietary Allowance, EAR = Estimated Average Requirement, AI =
Adequate Intake, UL = Tolerable Upper Intake Level.

Responding to the expansion of scientific knowledge about the roles of nutrients in human health, the Institute of Medicine has developed a new approach to establish Recommended Dietary Allowances (RDAs) and other nutrient reference values. The new title for these values Dietary Reference Intakes (DRIs), is the inclusive name being given to this new approach. These are quantitative estimates of nutrient intakes applicable to healthy individuals in the United States and Canada. This new book is part of a series of books presenting dietary reference values for the intakes of nutrients. It establishes recommendations for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids. This book presents new approaches and findings which include the following:

The establishment of Estimated Energy Requirements at four levels of energy expenditure

Recommendations for levels of physical activity to decrease risk of chronic disease

The establishment of RDAs for dietary carbohydrate and protein

The development of the definitions of Dietary Fiber, Functional Fiber, and Total Fiber

The establishment of Adequate Intakes (AI) for Total Fiber

The establishment of AIs for linolenic and a-linolenic acids

Acceptable Macronutrient Distribution Ranges as a percent of energy intake for fat, carbohydrate, linolenic and a-linolenic acids, and protein

Research recommendations for information needed to advance understanding of macronutrient requirements and the adverse effects associated with intake of higher amounts

Also detailed are recommendations for both physical activity and energy expenditure to maintain health and decrease the risk of disease.

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